Dondur, Vera

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orcid::0000-0003-3507-3966
  • Dondur, Vera (9)
Projects

Author's Bibliography

Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal

Omerašević, Mia; Ružić, Jovana; Vuković, Nikola; Jovanović, Uroš D.; Mirković, Miljana M.; Maksimović, Vesna; Dondur, Vera

(2016)

TY  - JOUR
AU  - Omerašević, Mia
AU  - Ružić, Jovana
AU  - Vuković, Nikola
AU  - Jovanović, Uroš D.
AU  - Mirković, Miljana M.
AU  - Maksimović, Vesna
AU  - Dondur, Vera
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1130
AB  - The possibility to use natural zeolite - clinoptilolite as a host material for radioactive Cs immobilization has been investigated. Cs-exchanged form of clinoptilolite which was prepared by treatment of clinoptilolite powder with 0.25 M CsCl solution was compacted. Both, powder and powder compact of exchanged clinoptilolite were thermally treated at 1200 C-0. The XRPD analysis showed that Cs was successfully immobilized after heat treatment by formation of stable cesium dodecaoxo-alumopentasilicate in both, powder sample and compact. The newly formed compound showed satisfactory Cs ions retention during leaching test. The sintered compact showed somewhat better resistance to Cs leaching than the thermally treated powder. The compressive strength of sintered compact was close to 200 MPa which is more than enough for easy handling and safe storage.
T2  - Science of Sintering
T1  - Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal
VL  - 48
IS  - 1
SP  - 101
EP  - 107
DO  - 10.2298/SOS1601101O
ER  - 
@article{
author = "Omerašević, Mia and Ružić, Jovana and Vuković, Nikola and Jovanović, Uroš D. and Mirković, Miljana M. and Maksimović, Vesna and Dondur, Vera",
year = "2016",
abstract = "The possibility to use natural zeolite - clinoptilolite as a host material for radioactive Cs immobilization has been investigated. Cs-exchanged form of clinoptilolite which was prepared by treatment of clinoptilolite powder with 0.25 M CsCl solution was compacted. Both, powder and powder compact of exchanged clinoptilolite were thermally treated at 1200 C-0. The XRPD analysis showed that Cs was successfully immobilized after heat treatment by formation of stable cesium dodecaoxo-alumopentasilicate in both, powder sample and compact. The newly formed compound showed satisfactory Cs ions retention during leaching test. The sintered compact showed somewhat better resistance to Cs leaching than the thermally treated powder. The compressive strength of sintered compact was close to 200 MPa which is more than enough for easy handling and safe storage.",
journal = "Science of Sintering",
title = "Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal",
volume = "48",
number = "1",
pages = "101-107",
doi = "10.2298/SOS1601101O"
}
Omerašević, M., Ružić, J., Vuković, N., Jovanović, U. D., Mirković, M. M., Maksimović, V.,& Dondur, V.. (2016). Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal. in Science of Sintering, 48(1), 101-107.
https://doi.org/10.2298/SOS1601101O
Omerašević M, Ružić J, Vuković N, Jovanović UD, Mirković MM, Maksimović V, Dondur V. Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal. in Science of Sintering. 2016;48(1):101-107.
doi:10.2298/SOS1601101O .
Omerašević, Mia, Ružić, Jovana, Vuković, Nikola, Jovanović, Uroš D., Mirković, Miljana M., Maksimović, Vesna, Dondur, Vera, "Removal of Cs Ions from Aqueous Solutions by Using Matrices of Natural Clinoptilolite and its Safe Disposal" in Science of Sintering, 48, no. 1 (2016):101-107,
https://doi.org/10.2298/SOS1601101O . .
3
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Safe trapping of cesium into pollucite structure by hot-pressing method

Omerašević, Mia; Matović, Ljiljana; Ružić, Jovana; Golubović, Željko; Jovanović, Uroš D.; Mentus, Slavko V.; Dondur, Vera

(Elsevier, 2016)

TY  - JOUR
AU  - Omerašević, Mia
AU  - Matović, Ljiljana
AU  - Ružić, Jovana
AU  - Golubović, Željko
AU  - Jovanović, Uroš D.
AU  - Mentus, Slavko V.
AU  - Dondur, Vera
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1038
AB  - A simple one-step method with direct thermal conversion at lower temperatures for preparing a stabile Cs-aluminsilicate phase, known as pollucite, is presented. Cs-exchanged form of Na, Ca-LTA type of zeolite (Cs-LTA) was pressureless sintered and hot pressed at certain temperatures in order to obtain pollucite. XRD and FTIR analysis were used to study structural changes of Cs-LTA before and after thermal treatments. Pressureless sintered sample recrystallized into pollucite phase after heat treatment at 1000 degrees C (3 h) (PLS1000) and hot pressed sample at 750 degrees C (3 h) using pressure of 35 MPa (HP750), indicating reduced temperature of 250 degrees. SEM micrographs confirmed that HP750 has higher density than PLS1000 which leads to higher value of compressive strength. The HP750 showed better resistance to Cs leaching than the PLS1000. Base on these results one can conclude that hot pressing is the promising method for the permanent disposal of Cs radionuclides. (C) 2016 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Journal of Nuclear Materials
T1  - Safe trapping of cesium into pollucite structure by hot-pressing method
VL  - 474
SP  - 35
EP  - 44
DO  - 10.1016/j.jnucmat.2016.03.006
ER  - 
@article{
author = "Omerašević, Mia and Matović, Ljiljana and Ružić, Jovana and Golubović, Željko and Jovanović, Uroš D. and Mentus, Slavko V. and Dondur, Vera",
year = "2016",
abstract = "A simple one-step method with direct thermal conversion at lower temperatures for preparing a stabile Cs-aluminsilicate phase, known as pollucite, is presented. Cs-exchanged form of Na, Ca-LTA type of zeolite (Cs-LTA) was pressureless sintered and hot pressed at certain temperatures in order to obtain pollucite. XRD and FTIR analysis were used to study structural changes of Cs-LTA before and after thermal treatments. Pressureless sintered sample recrystallized into pollucite phase after heat treatment at 1000 degrees C (3 h) (PLS1000) and hot pressed sample at 750 degrees C (3 h) using pressure of 35 MPa (HP750), indicating reduced temperature of 250 degrees. SEM micrographs confirmed that HP750 has higher density than PLS1000 which leads to higher value of compressive strength. The HP750 showed better resistance to Cs leaching than the PLS1000. Base on these results one can conclude that hot pressing is the promising method for the permanent disposal of Cs radionuclides. (C) 2016 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Journal of Nuclear Materials",
title = "Safe trapping of cesium into pollucite structure by hot-pressing method",
volume = "474",
pages = "35-44",
doi = "10.1016/j.jnucmat.2016.03.006"
}
Omerašević, M., Matović, L., Ružić, J., Golubović, Ž., Jovanović, U. D., Mentus, S. V.,& Dondur, V.. (2016). Safe trapping of cesium into pollucite structure by hot-pressing method. in Journal of Nuclear Materials
Elsevier., 474, 35-44.
https://doi.org/10.1016/j.jnucmat.2016.03.006
Omerašević M, Matović L, Ružić J, Golubović Ž, Jovanović UD, Mentus SV, Dondur V. Safe trapping of cesium into pollucite structure by hot-pressing method. in Journal of Nuclear Materials. 2016;474:35-44.
doi:10.1016/j.jnucmat.2016.03.006 .
Omerašević, Mia, Matović, Ljiljana, Ružić, Jovana, Golubović, Željko, Jovanović, Uroš D., Mentus, Slavko V., Dondur, Vera, "Safe trapping of cesium into pollucite structure by hot-pressing method" in Journal of Nuclear Materials, 474 (2016):35-44,
https://doi.org/10.1016/j.jnucmat.2016.03.006 . .
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Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases

Radosavljević-Mihajlović, Ana S.; Kremenović, Aleksandar S.; Došen, Anja M.; Andrejic, J. Z.; Dondur, Vera

(2015)

TY  - JOUR
AU  - Radosavljević-Mihajlović, Ana S.
AU  - Kremenović, Aleksandar S.
AU  - Došen, Anja M.
AU  - Andrejic, J. Z.
AU  - Dondur, Vera
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/218
AB  - Thermally induced phase transformations of Pb-exchange LTA and FAU zeolites were from ambient temperature to 1300 degrees C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650 degrees C. Prolonged heating of the intermediate product over 1100 degrees C results in the formation of disordered Pb-feldspar(LTA) [a = 8.414 (4) angstrom, b = 13.048 (4) angstrom, c = 7.169 (4) angstrom, beta = 115.35 degrees (3)] and Pb-feldspar(FAU) [a = 8.422 (4) angstrom, b = 13.054 (4) angstrom, c = 7.173 (4) angstrom, beta = 115.37 degrees (3)] phases. The phase conversions within the investigated temperature range were followed by thermal (DTA, TGA, and DSC), XRPD, and Raman methods. (C) 2014 Elsevier Inc. All rights reserved.
T2  - Microporous and Mesoporous Materials
T1  - Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases
VL  - 201
SP  - 210
EP  - 218
DO  - 10.1016/j.micromeso.2014.08.059
ER  - 
@article{
author = "Radosavljević-Mihajlović, Ana S. and Kremenović, Aleksandar S. and Došen, Anja M. and Andrejic, J. Z. and Dondur, Vera",
year = "2015",
abstract = "Thermally induced phase transformations of Pb-exchange LTA and FAU zeolites were from ambient temperature to 1300 degrees C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650 degrees C. Prolonged heating of the intermediate product over 1100 degrees C results in the formation of disordered Pb-feldspar(LTA) [a = 8.414 (4) angstrom, b = 13.048 (4) angstrom, c = 7.169 (4) angstrom, beta = 115.35 degrees (3)] and Pb-feldspar(FAU) [a = 8.422 (4) angstrom, b = 13.054 (4) angstrom, c = 7.173 (4) angstrom, beta = 115.37 degrees (3)] phases. The phase conversions within the investigated temperature range were followed by thermal (DTA, TGA, and DSC), XRPD, and Raman methods. (C) 2014 Elsevier Inc. All rights reserved.",
journal = "Microporous and Mesoporous Materials",
title = "Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases",
volume = "201",
pages = "210-218",
doi = "10.1016/j.micromeso.2014.08.059"
}
Radosavljević-Mihajlović, A. S., Kremenović, A. S., Došen, A. M., Andrejic, J. Z.,& Dondur, V.. (2015). Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases. in Microporous and Mesoporous Materials, 201, 210-218.
https://doi.org/10.1016/j.micromeso.2014.08.059
Radosavljević-Mihajlović AS, Kremenović AS, Došen AM, Andrejic JZ, Dondur V. Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases. in Microporous and Mesoporous Materials. 2015;201:210-218.
doi:10.1016/j.micromeso.2014.08.059 .
Radosavljević-Mihajlović, Ana S., Kremenović, Aleksandar S., Došen, Anja M., Andrejic, J. Z., Dondur, Vera, "Thermally induced phase transformation of Pb-exchanged LTA and FAU-framework zeolite to feldspar phases" in Microporous and Mesoporous Materials, 201 (2015):210-218,
https://doi.org/10.1016/j.micromeso.2014.08.059 . .
8
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Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment

Hercigonja, Radmila V.; Maksin, Danijela D.; Dondur, Vera

(Society of Physical Chemists of Serbia, 2010)

TY  - CONF
AU  - Hercigonja, Radmila V.
AU  - Maksin, Danijela D.
AU  - Dondur, Vera
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9332
AB  - Aluminum ions were extracted from the framework of the faujasite type zeolite NaY
(Si/Al=2.4) by citric acid treatment. Dealuminated CoY and ZnY zeolites of high cobalt
and zinc content were prepared by replacing sodium ions with Co2+ and Zn2+ in
dealuminated Y zeolites, with increased framework Si/Al ratio. Chemical and XRD
analyses of zeolites were performed and the FTIR-ATR spectra were recorded. The
results of physicochemical analyses are discussed in terms of unit cell (u.c.) composition.
PB  - Society of Physical Chemists of Serbia
C3  - Physical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry
T1  - Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment
ER  - 
@conference{
author = "Hercigonja, Radmila V. and Maksin, Danijela D. and Dondur, Vera",
year = "2010",
abstract = "Aluminum ions were extracted from the framework of the faujasite type zeolite NaY
(Si/Al=2.4) by citric acid treatment. Dealuminated CoY and ZnY zeolites of high cobalt
and zinc content were prepared by replacing sodium ions with Co2+ and Zn2+ in
dealuminated Y zeolites, with increased framework Si/Al ratio. Chemical and XRD
analyses of zeolites were performed and the FTIR-ATR spectra were recorded. The
results of physicochemical analyses are discussed in terms of unit cell (u.c.) composition.",
publisher = "Society of Physical Chemists of Serbia",
journal = "Physical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry",
title = "Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment"
}
Hercigonja, R. V., Maksin, D. D.,& Dondur, V.. (2010). Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment. in Physical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry
Society of Physical Chemists of Serbia..
Hercigonja RV, Maksin DD, Dondur V. Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment. in Physical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry. 2010;..
Hercigonja, Radmila V., Maksin, Danijela D., Dondur, Vera, "Introduction of transition metal cations (Co2+ and Zn2+) into dealuminated NaY zeolite obtained by citric acid treatment" in Physical chemistry 2010 : 10th international conference on fundamental and applied aspects of physical chemistry (2010).

The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis

Novaković, Tatjana ; Radić, Nenad; Grbic, Bosko; Dondur, Vera; Mitrić, Miodrag; Randjelovic, Danijela; Stoychev, Dimitar; Stefanov, Plamen

(2008)

TY  - JOUR
AU  - Novaković, Tatjana 
AU  - Radić, Nenad
AU  - Grbic, Bosko
AU  - Dondur, Vera
AU  - Mitrić, Miodrag
AU  - Randjelovic, Danijela
AU  - Stoychev, Dimitar
AU  - Stefanov, Plamen
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3582
AB  - Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La(3+) in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented. It was found that the addition of polyethylene glycol combined with La3+ to the boehmite sol before spraying improves the thermal stability of porous alumina coatings. X-ray diffraction patterns of a doped sample, even after 5 h at 1000 degrees C, point out to the presence only of delta-Al(2)O(3), with a S(BET) of 74 m(2)/g. XPS data and SEM photographs of coated samples show that alumina were well deposited on the metallic supports. The absence of any lanthanum compounds indicates very well homogeneous dispersion of La(3+)-ions on the surface of alumina crystallites. AFM images show sphere like alumina grains and agglomerates with surface roughness from 60 to 180 nm, depending on temperature and doping. Surface roughness of doped alumina samples was higher than that of non-doped. It was pointed out that spray pyrolysis method enables preparation of alumina layers with relatively high specific surface area, suitable for applications as catalysts supports. (C) 2008 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis
VL  - 255
IS  - 5
SP  - 3049
EP  - 3055
DO  - 10.1016/j.apsusc.2008.08.074
ER  - 
@article{
author = "Novaković, Tatjana  and Radić, Nenad and Grbic, Bosko and Dondur, Vera and Mitrić, Miodrag and Randjelovic, Danijela and Stoychev, Dimitar and Stefanov, Plamen",
year = "2008",
abstract = "Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La(3+) in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented. It was found that the addition of polyethylene glycol combined with La3+ to the boehmite sol before spraying improves the thermal stability of porous alumina coatings. X-ray diffraction patterns of a doped sample, even after 5 h at 1000 degrees C, point out to the presence only of delta-Al(2)O(3), with a S(BET) of 74 m(2)/g. XPS data and SEM photographs of coated samples show that alumina were well deposited on the metallic supports. The absence of any lanthanum compounds indicates very well homogeneous dispersion of La(3+)-ions on the surface of alumina crystallites. AFM images show sphere like alumina grains and agglomerates with surface roughness from 60 to 180 nm, depending on temperature and doping. Surface roughness of doped alumina samples was higher than that of non-doped. It was pointed out that spray pyrolysis method enables preparation of alumina layers with relatively high specific surface area, suitable for applications as catalysts supports. (C) 2008 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis",
volume = "255",
number = "5",
pages = "3049-3055",
doi = "10.1016/j.apsusc.2008.08.074"
}
Novaković, T., Radić, N., Grbic, B., Dondur, V., Mitrić, M., Randjelovic, D., Stoychev, D.,& Stefanov, P.. (2008). The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis. in Applied Surface Science, 255(5), 3049-3055.
https://doi.org/10.1016/j.apsusc.2008.08.074
Novaković T, Radić N, Grbic B, Dondur V, Mitrić M, Randjelovic D, Stoychev D, Stefanov P. The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis. in Applied Surface Science. 2008;255(5):3049-3055.
doi:10.1016/j.apsusc.2008.08.074 .
Novaković, Tatjana , Radić, Nenad, Grbic, Bosko, Dondur, Vera, Mitrić, Miodrag, Randjelovic, Danijela, Stoychev, Dimitar, Stefanov, Plamen, "The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis" in Applied Surface Science, 255, no. 5 (2008):3049-3055,
https://doi.org/10.1016/j.apsusc.2008.08.074 . .
20
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Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites

Nedić, B.; Dondur, Vera; Kremenović, Aleksandar S.; Dimitrijevic, R.; Antić, Bratislav; Blanuša, Jovan; Vasiljević-Radović, Dana; Stoiljković, Milovan

(2007)

TY  - JOUR
AU  - Nedić, B.
AU  - Dondur, Vera
AU  - Kremenović, Aleksandar S.
AU  - Dimitrijevic, R.
AU  - Antić, Bratislav
AU  - Blanuša, Jovan
AU  - Vasiljević-Radović, Dana
AU  - Stoiljković, Milovan
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6720
AB  - Yb3+-doped Ba and Sr diphyllosilicates (hexacelsians) have been synthesized using the Na form of LTA zeolite by ion-exchange procedure and thermal treatment. The crystal structures of both doped samples are refined and described in this article. The results of Rietveld refinements clearly indicate that Yb3+ ions are incorporated into the hexacelsians structure. AFM photomicrographs show round-shaped particles with the size of few microns. The magnetization measurements were done within the 2-300 K temperature range, revealing an enhancement of magnetization with temperature that is not in accordance with simple paramagnetic behavior.
T2  - Russian Journal of Physical Chemistry A
T1  - Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites
VL  - 81
IS  - 9
SP  - 1413
EP  - 1417
DO  - 10.1134/S0036024407090129
ER  - 
@article{
author = "Nedić, B. and Dondur, Vera and Kremenović, Aleksandar S. and Dimitrijevic, R. and Antić, Bratislav and Blanuša, Jovan and Vasiljević-Radović, Dana and Stoiljković, Milovan",
year = "2007",
abstract = "Yb3+-doped Ba and Sr diphyllosilicates (hexacelsians) have been synthesized using the Na form of LTA zeolite by ion-exchange procedure and thermal treatment. The crystal structures of both doped samples are refined and described in this article. The results of Rietveld refinements clearly indicate that Yb3+ ions are incorporated into the hexacelsians structure. AFM photomicrographs show round-shaped particles with the size of few microns. The magnetization measurements were done within the 2-300 K temperature range, revealing an enhancement of magnetization with temperature that is not in accordance with simple paramagnetic behavior.",
journal = "Russian Journal of Physical Chemistry A",
title = "Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites",
volume = "81",
number = "9",
pages = "1413-1417",
doi = "10.1134/S0036024407090129"
}
Nedić, B., Dondur, V., Kremenović, A. S., Dimitrijevic, R., Antić, B., Blanuša, J., Vasiljević-Radović, D.,& Stoiljković, M.. (2007). Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites. in Russian Journal of Physical Chemistry A, 81(9), 1413-1417.
https://doi.org/10.1134/S0036024407090129
Nedić B, Dondur V, Kremenović AS, Dimitrijevic R, Antić B, Blanuša J, Vasiljević-Radović D, Stoiljković M. Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites. in Russian Journal of Physical Chemistry A. 2007;81(9):1413-1417.
doi:10.1134/S0036024407090129 .
Nedić, B., Dondur, Vera, Kremenović, Aleksandar S., Dimitrijevic, R., Antić, Bratislav, Blanuša, Jovan, Vasiljević-Radović, Dana, Stoiljković, Milovan, "Yb3+ doped dyphillosilicates prepared by thermally induced phase transformation of zeolites" in Russian Journal of Physical Chemistry A, 81, no. 9 (2007):1413-1417,
https://doi.org/10.1134/S0036024407090129 . .
2
4
4

The influence of the solid/liquid ratio on the point of zero charge of alumina

Todorović, Žaklina; Milonjić, Slobodan K.; Dondur, Vera

(2004)

TY  - JOUR
AU  - Todorović, Žaklina
AU  - Milonjić, Slobodan K.
AU  - Dondur, Vera
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6433
AB  - The point of zero charge (pH(pzc)) of three samples of commercial aluminum oxide in aqueous KNO3 (10(-3) - 10(-1) mol/dm(3)) solution was investigated using batch equilibration, mass titration and acid-base titration methods. Structural and chemical characteristics of the alumina samples were determined by X-ray diffraction (XRD) and energy-dispersive X-ray fluorescence spectroscopy (EDXRFS). The obtained pH(pzc) values (5 to 8.5) dependent on the alumina/solution ratio increase with increasing ratio to a constant value. The concentration of dissolved aluminum ions as a function of solution pH (pH = 3.5 - 11) exhibit a parabolic trend, with the minimum solubility at pHpzc.
T2  - Materials Science Forum
T1  - The influence of the solid/liquid ratio on the point of zero charge of alumina
VL  - 453-454
SP  - 361
EP  - 366
ER  - 
@article{
author = "Todorović, Žaklina and Milonjić, Slobodan K. and Dondur, Vera",
year = "2004",
abstract = "The point of zero charge (pH(pzc)) of three samples of commercial aluminum oxide in aqueous KNO3 (10(-3) - 10(-1) mol/dm(3)) solution was investigated using batch equilibration, mass titration and acid-base titration methods. Structural and chemical characteristics of the alumina samples were determined by X-ray diffraction (XRD) and energy-dispersive X-ray fluorescence spectroscopy (EDXRFS). The obtained pH(pzc) values (5 to 8.5) dependent on the alumina/solution ratio increase with increasing ratio to a constant value. The concentration of dissolved aluminum ions as a function of solution pH (pH = 3.5 - 11) exhibit a parabolic trend, with the minimum solubility at pHpzc.",
journal = "Materials Science Forum",
title = "The influence of the solid/liquid ratio on the point of zero charge of alumina",
volume = "453-454",
pages = "361-366"
}
Todorović, Ž., Milonjić, S. K.,& Dondur, V.. (2004). The influence of the solid/liquid ratio on the point of zero charge of alumina. in Materials Science Forum, 453-454, 361-366.
Todorović Ž, Milonjić SK, Dondur V. The influence of the solid/liquid ratio on the point of zero charge of alumina. in Materials Science Forum. 2004;453-454:361-366..
Todorović, Žaklina, Milonjić, Slobodan K., Dondur, Vera, "The influence of the solid/liquid ratio on the point of zero charge of alumina" in Materials Science Forum, 453-454 (2004):361-366.
10

The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide

Rakić, Vesna M.; Dondur, Vera; Hercigonja, Radmila V.; Andrić, Velibor

(2003)

TY  - JOUR
AU  - Rakić, Vesna M.
AU  - Dondur, Vera
AU  - Hercigonja, Radmila V.
AU  - Andrić, Velibor
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6374
AB  - The active sites of hydrogen-exchanged Y zeolite (HY) and dealuminated (HDY) zeolites are investigated by TPD of carbon monoxide. Only the high temperature TPD spectra of CO (T(M)approximate to620-690degreesC) were observed, meaning that CO molecules interact with very strong acid sites. The amounts of CO bonded on these sites are small (less than 1 molecule per unit cell). The strong influence of dealumination on the coverage degree is found. The calculated values for kinetic parameters indicate chemisorption of CO in the investigated systems (E(des)approximate to240 kJ mol(-1), Aapproximate to10(11) s(-1)).
T2  - Journal of Thermal Analysis and Calorimetry
T1  - The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide
VL  - 72
IS  - 3
SP  - 761
EP  - 767
DO  - 10.1023/A:1025049727731
ER  - 
@article{
author = "Rakić, Vesna M. and Dondur, Vera and Hercigonja, Radmila V. and Andrić, Velibor",
year = "2003",
abstract = "The active sites of hydrogen-exchanged Y zeolite (HY) and dealuminated (HDY) zeolites are investigated by TPD of carbon monoxide. Only the high temperature TPD spectra of CO (T(M)approximate to620-690degreesC) were observed, meaning that CO molecules interact with very strong acid sites. The amounts of CO bonded on these sites are small (less than 1 molecule per unit cell). The strong influence of dealumination on the coverage degree is found. The calculated values for kinetic parameters indicate chemisorption of CO in the investigated systems (E(des)approximate to240 kJ mol(-1), Aapproximate to10(11) s(-1)).",
journal = "Journal of Thermal Analysis and Calorimetry",
title = "The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide",
volume = "72",
number = "3",
pages = "761-767",
doi = "10.1023/A:1025049727731"
}
Rakić, V. M., Dondur, V., Hercigonja, R. V.,& Andrić, V.. (2003). The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide. in Journal of Thermal Analysis and Calorimetry, 72(3), 761-767.
https://doi.org/10.1023/A:1025049727731
Rakić VM, Dondur V, Hercigonja RV, Andrić V. The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide. in Journal of Thermal Analysis and Calorimetry. 2003;72(3):761-767.
doi:10.1023/A:1025049727731 .
Rakić, Vesna M., Dondur, Vera, Hercigonja, Radmila V., Andrić, Velibor, "The investigation of strong active sites of dealuminated Y-type zeolite by TPD of carbon monoxide" in Journal of Thermal Analysis and Calorimetry, 72, no. 3 (2003):761-767,
https://doi.org/10.1023/A:1025049727731 . .
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Synthesis of Si3N4-celsian composite materials

Bošković, Snežana B.; Kosanovic, D; Dondur, Vera; Dimitrijevic, R

(2000)

TY  - JOUR
AU  - Bošković, Snežana B.
AU  - Kosanovic, D
AU  - Dondur, Vera
AU  - Dimitrijevic, R
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2298
AB  - The synthesis of Si3N4-celsian composite materials was studied in this paper. To obtain celsian, two different types of additives were used. In the first case the appropriate mixture of BaCO3, Al2O3 and SiO2 was added to Si3N4, while in the second case a Ba-A-zeolite, previously heated at 850 degrees C, was used as an additive. Mixtures of Si3N4 and the sintering aids were homogenized in a vibratory mill in the presence of isopropanol. The green bodies were pressurelessly sintered in nitrogen atmosphere at temperatures of 1650-1750 degrees C. Densification degree was followed, as well as microstructural changes, as a function of the sintering conditions and the additive used. Reaction of BAS formation was followed by X-ray analysis during the heating up period. It was found that with 10% zeolite as a sintering aid, full densification was achieved at 1750 degrees C but with the same amount of oxide mixture, only 96% TD was attained. Phase changes were followed also during cooling down the samples from sintering temperature. Two crystalline phases, beta-Si3N4 and hexacelsian, were present in both types of sintered samples. (C) 1999 Elsevier Science Ltd and Techna S.r.l. All rights reserved.
T2  - Ceramics International
T1  - Synthesis of Si3N4-celsian composite materials
VL  - 26
IS  - 1
SP  - 33
EP  - 37
DO  - 10.1016/S0272-8842(99)00016-4
ER  - 
@article{
author = "Bošković, Snežana B. and Kosanovic, D and Dondur, Vera and Dimitrijevic, R",
year = "2000",
abstract = "The synthesis of Si3N4-celsian composite materials was studied in this paper. To obtain celsian, two different types of additives were used. In the first case the appropriate mixture of BaCO3, Al2O3 and SiO2 was added to Si3N4, while in the second case a Ba-A-zeolite, previously heated at 850 degrees C, was used as an additive. Mixtures of Si3N4 and the sintering aids were homogenized in a vibratory mill in the presence of isopropanol. The green bodies were pressurelessly sintered in nitrogen atmosphere at temperatures of 1650-1750 degrees C. Densification degree was followed, as well as microstructural changes, as a function of the sintering conditions and the additive used. Reaction of BAS formation was followed by X-ray analysis during the heating up period. It was found that with 10% zeolite as a sintering aid, full densification was achieved at 1750 degrees C but with the same amount of oxide mixture, only 96% TD was attained. Phase changes were followed also during cooling down the samples from sintering temperature. Two crystalline phases, beta-Si3N4 and hexacelsian, were present in both types of sintered samples. (C) 1999 Elsevier Science Ltd and Techna S.r.l. All rights reserved.",
journal = "Ceramics International",
title = "Synthesis of Si3N4-celsian composite materials",
volume = "26",
number = "1",
pages = "33-37",
doi = "10.1016/S0272-8842(99)00016-4"
}
Bošković, S. B., Kosanovic, D., Dondur, V.,& Dimitrijevic, R.. (2000). Synthesis of Si3N4-celsian composite materials. in Ceramics International, 26(1), 33-37.
https://doi.org/10.1016/S0272-8842(99)00016-4
Bošković SB, Kosanovic D, Dondur V, Dimitrijevic R. Synthesis of Si3N4-celsian composite materials. in Ceramics International. 2000;26(1):33-37.
doi:10.1016/S0272-8842(99)00016-4 .
Bošković, Snežana B., Kosanovic, D, Dondur, Vera, Dimitrijevic, R, "Synthesis of Si3N4-celsian composite materials" in Ceramics International, 26, no. 1 (2000):33-37,
https://doi.org/10.1016/S0272-8842(99)00016-4 . .
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